The use of magnetic particles as markers in biomedical technology has long been known. In particular, following the appearance of magnetic nanoparticles it has already been proposed to use such a system for localizing magnetic markers in the form of accumulations of magnetic nanoparticles as part of analytical and/or diagnostic methods. So-called drug targeting methods, or else general tomographic imaging methods, for example, are understood here as diagnostics.
Such a tomographic imaging method in which nonlinear response signals of magnetic particles are evaluated is known from Nature, vol. 43530, June 2005-Letters, pages 1214 et seq., the entire contents of which are hereby incorporated herein by reference. Furthermore, an international patent application WO 2006/064 405 A1 is pending to this end, the entire contents of which are hereby incorporated herein by reference. The patent application describes in detail a method for determining the spatial distribution of the magnetic particles.